Nf=2 Lattice QCD and Chiral Perturbation Theory

TL;DR

This paper compares lattice QCD results with Wilson Chiral Perturbation Theory using twisted mass fermions to determine low energy constants, analyzing data across various lattice parameters for consistency and scaling behavior.

Contribution

It provides a comprehensive comparison of Nf=2 lattice QCD data with WChPT, assessing the theory's applicability and extracting low energy constants.

Findings

WChPT effectively describes lattice data across different parameters.

Scaling behaviors are confirmed in the continuum limit.

Determination of Gasser-Leutwyler Low Energy Constants.

Abstract

By employing a twisted mass term, we compare recent results from lattice calculations of Nf=2 dynamical Wilson fermions with Wilson Chiral Perturbation Theory (WChPT). The final goal is to determine some combinations of Gasser-Leutwyler Low Energy Constants (LECs). A wide set of data with different lattice spacings (a ~ 0.2-0.12 fm), different gauge actions (Wilson plaquette, DBW2) and different quark masses (down to the lowest pion mass allowed by lattice artifacts and including negative quark masses) provide a strong check of the applicability of WChPT in this regime and the scaling behaviours in the continuum limit.